Guys help me out here. I have a co-worker with a Seville STS with the Northstar in it, is this motor recomended premium fuel? I think it is and he tells me it isn't. Can someone solve this for me.

It is recommended that it runs on 92 octane, but can run on any fuel, it has very sensitive antiknock sensors. So if you run it on regular or mid grade... you wont get knock but the timing is being pulled, your performance limited, and your gas mileage goes down. It is worth the 7-10 cents to run what it wants, and was designed for

Thanks, for the info....